Structures of neutral and anionic Au(16) clusters revisited

Area of Science:

• Computational Chemistry
• Materials Science
• Surface Science

Background:

• Understanding the structure and properties of gold clusters is crucial for catalysis and nanotechnology.
• Investigating neutral and anionic gold clusters (Au(16)) reveals insights into their unique electronic and geometric characteristics.

Purpose of the Study:

• To identify the ground state geometries of neutral and anionic Au(16) clusters using extensive computational searches.
• To elucidate the stability and formation mechanisms of Au(16) and Au(16)⁻.
• To compare calculated photoelectron spectra with experimental data to validate structural assignments.

Main Methods:

• Density Functional Theory (DFT) with generalized gradient approximation (GGA) for electronic structure calculations.
• Extensive isomer search considering over 200 low-lying configurations.
• Molecular dynamics simulations to study cluster dynamics and stability.
• Photoelectron spectroscopy calculations for experimental comparison.

Main Results:

• A new T(d) compact structure identified as the lowest energy configuration for neutral Au(16), nearly degenerate with previously reported structures.
• An isomer with a planar structure found to be the lowest energy configuration for the Au(16)⁻ cluster, differing from the T(d) hollow cage.
• Calculated photoelectron spectra align with experimental data, aiding in the identification of stable isomers.

Conclusions:

• The study reveals distinct lowest energy structures for neutral and anionic Au(16) clusters, challenging previous assumptions.
• It provides explanations for the near-identical adiabatic and vertical detachment energies despite structural differences.
• The findings offer insights into the formation process of Au(16)⁻, addressing whether it forms as a neutral or anionic species.